Fluid pressure control apparatus



Sept. 20, 1949. R. J. BUSH FLUID PRESSURE CONTROL APPARATUS 5 Sheets-Sheet 1 Filed March 23, 1943 .6305 wm m Haw E man 0mm m @QN mam 8P] 8 0% 0% 9% 930 m mcm 8n Rankin JBush BY 612.1%

ATTORNEY Sept. 20, 1949. R. J. BUSH 2,432,244

FLUID PRESSURE CONTROL APPARATUS Filed March 25, 1943 5 Sheets-Sheet 2 w 2 1 2 w a A w. 8 U V 7 Z 2 2 J R H 7& 1 4% .Q M 68 8 21 N 8 2 m E H m 5 V. i T 5. m w w A W Wm A 9 7 W.%2 A 8 H a i ow #2 1 1L ,r vm f H X L Q A A m A 5 v v; 6 V All 7. m i I & a i a W0 N 2 y 0 ll. 0 9 M 7776766 in? 227.2227 E 4 5 NW 2 7. 10 2 2 2 ("O 2 B I 7564 92%5 w m m mmmmmwwmmwwwzz a 2 v w A .5 4 A 2 A a 4L 8 a a, i .2 J 44 M B v i 1 11 I 9 x a g w w 1 a mmv ma 9, 51 5 1 R KP: 73 iams m 5 4 .g 1 1 1 A 1 1/ G M 2 a4 N 6 J1 If wiihp A 1 A 9 ZWJ V P 1 Q w h- 4 A E pu mm w a 6 5 Sept. 20, 1949. R. J. BUSH FLUID PRESSURE CONTROL APPARATUS 5 Sheets-Sheet 3 Filed March 25, 1943 INVENTOR Fankz'n J Bush BY QZW ATTORNEY Sept. 20, 1949. R. J. BUSH FLUID PRESSURE CONTROL APPARATUS Filed March 23, 1943 5 Sheets-Sheet 4 A I. as

fig, .14

Z" 515 I "3 '564 C 502 561 1' 5 "I. y i 30? 2?; {m 51% I" 52o gi /.4 560 504 INVENTOR Eanlrin J flush ATTORNEY Sept. 2%, 19490 R. J. BUSH FLUID PRESSURE CONTROL APPARATUS 5 Sheeis-Sheet 5 Filed March 23, 1943 6F 3 J Q g Q Sm $3M mom. N. omw NS EN EN E a Om mm. Q 8 3w u 0 @w 0 x. @NN Q 08$ 9% o Q 5 a? on Q N8 r D Q fin 2m m 0 mg 0% m mom H a3 3 ONLN V Nn 1 3 @pm @a 8? 9 @9 E g 8 w @2 mm @v. N N wm O r P QM @Q 5 NE $9 02 $2 Q fiw v i 4 5 OH QM 09 mm Wm ATTORN EY Patented Sept. 20, 1949 2,482,244 FLUID .PBESSUBE TEQL ,e AB TIE Rankin J. Bush, Jeannette, Pa, .assignor .to The We tin hou e ilBrake Comnany, am nd n Be a co ceere en P ennsxlten eevli eiiee M w- 4? e a N 0 1 1 Ihis invention relates to control apparatus and more iiarticula-rly' to the fluid pressure type for selectively controlling a plurality of diiferent 'opera'tions ordeviee'sJ Certain large airplanes provided with a plurality or' ba nk of internal combustion propelling "engines; at either "side of the fuselage require, in addition" tghthe pilot who controls the 'sliveed'of -both-banks of engines during flight, an engineer for constantly Watching the operation of each "indiviiiu'al engine through ithe rnedium of gages or the like and for making such adjustments as may he required to provide desired and efiicient ppration of the engines under different; flight conditions. At-the discretion oft-he pilot, Orrin case of emergency, the engineer should be capable of pnt f ine t efe eie durin flight mmo when not in flight; as during" warmingup periods or 1:01 th purpos :of max m; he plen :MQ rover, if durin flig t tro ble 9f any kin shou d ieeve p in e n h en i ee S o ld b e o ea th en i e QQU of s etr the PM J 9 z-reneir n h likeendr he i f esir djsut equ ni itrensf su hw oh re ,baq e th lpile fineohjeetgpf the invention vis th iefqrethe rn'ovision @of a, ure systernlfor eon;- i oll n e .Pll i' Zl me w re s h as nternafl 99ml; stiph engines, from either of tvvp t ent-rp st t' ne u h p' sn i e s coinpartm ens j AtiQ fi i i lt f h -,i v timii, he r vi ion of, a fitfid pressure pet rsystemxrbr ai'plurf ty er seems internal. ornbustiori engines prbviidi n e et', 11 tithes, {for gont'rol p' tne' engin er of rl engine, such ,as ,[a ,supereharger "and of ,ni'eans governing the fuel ,mixture to and the tein, ,e'ratur'e -of' ls uch ,mi itllre for said engine, I and also PZ' QV idiIig'iOI control of the speed 'of the engines 'gingivi duallyhy,theengineer pr of the bank of engines, as a unit, by the pilot.

' ienp he .obie 0 the in enti n i th QYis of a eontr'ol'systein such" as defined inthe'preeeding,oltijects whereby the pilot can, at will,

,take fover the eontrol of the speed of an engines regardlesslof the enginn'er, if all engines are working; andJmay, at will, return such control td the enineer.

flhe proposed pilots control of speed of a; bank of engines' provides-for simultaneous and like 'adjustfiient'sof the speed of all enginesinth bank. =Due to -s1ight..difierencesvihichlhowever may exist in d-i-fiernt parts-of eachengine and the adj.ustamentrthereof and [or of controllinggevices. there- ;fbf, .017 :in :the ,pitch .of the ..propeller sdriven by 'cpntr'oll'ingdevices for each individual 1;:

the engine, such simultaneous control of all eng nes "in th'e'bank" mayi'not provide identical operation, such as "sne'ed'or output of all engines. 'Afiothr sweet er the invention is therefore the provision of means controlled by the engineer for synchronizing the operation or equalizing the 0mm of each engine in a bank With'all other enginesfin' the bank while the speed! of all' of "the eng neers under the cemml of the pilot. ""Anotherobject of th'invention'is the provision of whereby in case of difficulty with any individual engine, "the engi eer may out said engineom of eo'ntr'olby' thebilot'ior correctin theidi fficulty, andthenifdesii ed, return the con} t'r'o1 of said engine to th epi'lot'.

Another objeet gf the invntionis the provision of a fluid pressure control S stem, suehas defined in anv'of the above objects, which is so con- ,structed and arr anged as to insure substantially the sam'and t oiible freeopration of thef'en- Another object qf the invention isthe provision of a "fluid l pressjure control sv'stein as above defined so arranged that the failure of any one "control pipe willha've no'jeffe'fo't upon other parts 0 ,the ystem; hu t a ure of Pipe hi inight possibly result ,in iailure of one engine,

will .havle r1o;e1iegt,upbn operation fany other Another object of the invention is the provi on fl lu d res ure c ntm msu e above "defined which embodies a plurality fof so rce Qffi i de mess e Qr e p su desi ed; c r tro go j he' lan in as o ur p one or another of said sources.

Qt'her objects and advantages Will be apparent rfror'nj't'he following inorejdetailed description-of theinvention:

In the accompanying drawings; Fig. 1 is a valve' de'viee shown in elevation'inFig. 1'; Figs. 3 and 4 are secti'onalview's taken 'onthelines 3- 3 and 44, respectively, in FigVZ; Fig. .5 is

a vertical sectional View '01 a portion of an engineer s speed'control valve device arrangeclto weontrol-the speed of one engine and shown in elevation in Fig.1; Figswfi, '7, an d,8 fare vertical l-sectional viewsitak'en .on lines" 66, 1..?, fand 8 8 ,..,i'espeetively, .of. an engineers ,-control valve devieelshown in elevation in Fig. 1; Figs. 9, 1 0 and 11 are se tiona viewsfl wqe tai deviqe 3 shown in elevation in Fig. 1; Fig. 12 is a diagrammatic view, partly in section and partly in outline, of a modified form of control system embodying the invention; and Fig. 13 and 14 are sectional views taken on lines I3-I3 and I l-i4. respectively, in Fig. 12.

Description The invention will hereinafter be described as for controlling the speed or output of one or moreprime movers such as internal combustion engines and the adjustment of certain controlling devices for each engine, as applied to an airplane, but it is not intended that the invention be so limited, since from the following description it will be apparent that the system may, if desired, be equally well used for controlling the operation of one or more engines employed for purposes other than propelling an airplane.

As shown in Fig. 1 of the drawings, the dot and dash enclosures designated by reference numerals I to 4 indicate four internal combustion engines constituting one bank of engines intended to be located at one side of the fuselage of the plane. A like bank of engines will be located at the opposite side of the planes fuselage. The number of engines in each bank is immaterial to the invention since it is applicable to any desired number, four being chosen merely for illustrative purposes. shown in the drawings therefore provides for the control of only one bank of four engines, although it may be arranged to control a greater or lesser number of engines if desired. A duplicate control system would be provided for the bank of engines at the opposite side of the fuselage, but neither are shown in the drawings since they are not essential to a clear understanding of the invention.

Each of the engines I to 4 inclusive is provided with a fuel control device 400 having levers MI, 402 and 403 which are operative, respectively, to control the amount of fuel mixture supplied to the engine, the richness or leanness of said mixture and the temperature of said mixture. Each engine is also provided with a blower or supercharger 404 for driving the fuel mixture into the cylinders of the engine, a lever 405 being provided for controlling the operation of said blower. The

proper adjustment of all of these levers is required to obtain desired operation of the individual engines, and which operation may vary ac cording to difierent operating conditions of the airplane.

For adjusting the levers MI, 402, 403 and 405, there is associated with each engine four fluid pressure controlled regulating devices 5, 6, I, and 8 respectively, to which said levers are operatively connected. The devices 5 may be named speed regulating devices and are arranged to be controlled by either the pilot or the engineer of the airplane. The regulating devices 5, I, and 8 are arranged for control only by'the engineer and .may be named, respectively, mixture regulating devices, temperature regulating devices and blower or supercharger regulating devices.

All of the speed regulating devices 5 associated with the one bank of engines are arranged to be controlled, as a unit, i. e., simultaneously by means of a pilots speed control valve device III located at the pilots control station in the plane. In Fig. 1, two of the devices ID are shown arranged side by side, this arrangement constituting the pilots control for the two banks of engines located at opposite sides of the fuselage.

The fluid pressure control system 4 The speed regulating devices 5 associated with the engines I to 4 inclusive are also arranged to be individually controlled by the engineers speed control valve devices II, I2, I3, and I4, respectively, located at the engineers control station in the plane. The control valve devices II to I4 are identical to each other and are preferably built as a unit or 'with a common housing I5 to minimize the number of pipes in the system and thus the possibility of loss of control due to pipe breakage.

The reference numerals I6, II, I8, and I9 indicate four engineers fuel mixture control valve devices for controlling the mixture regulating devices 6 for the four engines I to 4, respectively. The reference numerals 20, 2I, 22, and 23 indicate four engineers temperature or heat control valve devices for controlling the temperature regulating devices I for the engines I to 4, respectively, while the reference numerals 24, 25, 26, and 21 indicate four blower control valve devices for controlling the regulating devices 8 for the engines I to 4 respectively. The several control devices IE to 21 are also preferably built with a common housing, indicated in Fig. 1 by reference numeral 28 to minimize the use of piping.

It will now be noted that the pilot is provided with the single control device In for governing, as a unit, the speed of all engines I to 4, while the engineer is provided with separate control devices for each individual engine for controlling its speed, the richnessor leanness of the fuel mixture, the temperature of said mixture, and the operation of the supercharger or blower. A more detailed description of these control devices and their manner of control will follow.

Description. of fluid pressure supply system Fluid under pressure for controlling the operation of the several devices 5 to 8 associated with the engines I to 4, inclusive, in either or both banks of engines, and, if desired, for also controlling any other fluid pressure responsive apparatus on the airplane is arranged to be provided by one or more fluid compressors 30 which may be driven by any suitable means such as said engines. The compressor 30 has an intake pipe 3| leading from a so-called sump reservoir 32 which, as will be later described, is arranged to receive, through a return pipe 33, fluid under pressure which has been used for operating the devices 5 to 8 or other apparatus. The sump reservoir 32 is also provided with an intake pipe 34 leading from the atmosphere and containing a check valve 35 arranged to prevent flow of fluid under pressure from the reservoir to the atmosphere.

Fluid under pressure discharged by the compressor 30 flows through a discharge pipe 36 to a main storage reservoir 31 and from thence past a check valve 38 to a second storage or auxiliary reservoir 39. From the reservoir 39 fluid under pressure flows through a cut-off valve device 49, a pipe 4|, a choke 42, and then past a check valve 43 to an emergency reservoir 44, thus all of the reservoirs 31, 39, and 44 may become charged with fluid at the same pressure which may be of r a relatively high degree such as 400 pounds per square inch.

the operation of the devices 5 to 8 upon initial "charging of the which will hereinafter be more fullS described.

The auxiliar reservoir 3'9 and emergency reseryou it constitute two separatefsour'ces or fluid under pressure for controlling the operation of the devices '5 to is associated With engines I to 4 as will be more fully described later, and to this "end the auxiliary reservoir-e9 is provided with a 'fluid pressure supply pipe #5 leading to the pilots eontnu valve device H1 and to the body 'H') or the engineers confirm v'al've devices 1| to l4, while the emergency reservoir t is provided with two m'deperraent fluid pressure supply pipes '46 and 4-1 leading respectively tostl're pilots control valve devise] a and to body is r the engineer's control 'jialtie devices I! to M. Cut-elf valve devices 48, 49, and 50 "are secured to the reservoirs 3'9 "and M in the connections between said reservoirs and the pipes 45, 45, and "E1, respectively, v i The cut-off valve devices 50,48,451, and 50 may be of identical "structure comprising, as shown in Fig. 11, a pony 'arra'nged to be secured to the repe'etive reservoir and containing a valve piston '52 "one end of which is arranged to seat against a gasket "53 To! closing "communication "between a passage "5 o'p'e'nt'o the interior of the reservoir "and outletp'a'ssage '5"! open to the respective pipe 41, 45, 46, "or spring 55 acts on the one end "of valve piston 52 urging same to its normal "or open position "shown, in which fluid under pressure may flow from the reservoir past the valvepi'ston to the respective pipe. The opposite end of valve piston 52 is subject to pressure "of "fluid in a chamber 56 which is connected througha restrictedfportWto passage 54 and-also througha passage 58-to the interior of the reseryou. "Tnthe "present structure therestricted port 51 serves "no useful pupose but is required in -"s'tr uctures to "be later described.

With the valve piston 52 in the open position shown, in which 'it will be maintained by spring "55 when the pressure of fluidinthe outlet passage 51 is within a'ceftain degree 'ofthat in the reseryou, new under pressure will freely flow from said reservoir to -"said passage and thence to the J respective pipe. A certain reduction in pressure "on the s ring -'engaged end or the valve piston 52, as in case of rupture of pipe-H 45,-' l6,or "4-1, will "liowe'vr perxriit the pressure of fluid in chamber 56 tomove the valve piston 5'12 against spring 55 "into sealingengag'ement viii'th gaskefi53 and thus 'cl'o'se communication between the reservoirand "pipe and prevent lessor fluid under pressure from said reservoir.

It will thus be seen that incase pipe ES should beco'rne ruptured,'tlre cut-ofi valve device 48 will close and prevent loss of fluid under pressure "from theauXiIiary reservoir 39, under which condition the supply or fluid-under pressure to the pil'ots eo'ritrol valve device "Ill and theengineer s controlv'alvedevices II to M will be maintained thiou'gh pipesfJ6 and '41. In case either or both "of 'pi'pes 46or l! should become rupturedfa supply of "fluidul'n'der pressure to the valve devices 18 to M will be maintained through pipe 45. Ifpipe I"! enema become ruptured, the cut-off valve-device El vvill-close to hold'the fluid pressure in the auxiliary reservoir "39 ahd therebymaiiit-ain the supplyornuiuunderpressure through pipets to the pilot and engineer control valve devices ID "to 1-4. I the auxiliar reservoi as itselfshodld 'ruptiire, the -'c'l-.e'c k valve '43 will act to bottle the fluidpres'sureinthe emergency reser-voir fl and thus maintain through *pipes and -41 "a supply of fluid "under pressure "to the pilot and 'en'gin-eer'is eontrol valve devices 10 to $4. The check valve 38 will act in a like capacity in case of rupture of the main "reservoir 31 or failure of the compressor 36. It will thus be seen that the possibility of loss of fluid under pressure for controlling the operation of the devices '5 to 8 at the several engines is reduced to a minimum.

The sup ly of fluid under pressure to the engineers control valve devices 1 8 to 21 is obtained from the reservoirs 3'9 and 44 through a pipe 35 by way of casing '15 of the engineers control valve devices I! to M, so that as long as the supply of fluid is maintained to the latter it will also be maintained to the formerexcept in case of breakageof'pi-pe "B5. The possibility of pipe 65 becoming ruptured however is remote since the engines control devices H to 21 vvfll an be located at the same control station and in relatively close proximity to each other.

In'c'ase one'of the pipes 41, 15,46, or 41 should break and cause closure of the respective cut-off valve device, then in order to effect movement of the valve piston 52 therein back to its open position shown in Fig. 11 after repair of the damage, it is necessary to reduce the difi ereri'tial in fluid pressures acting on said piston to a .degree less than the opposing force .of spring 55. In the cu -off valve devices so far described, this may be accomplished .by the :provision or a communication :by-pa'ssing the valve piston .52 and controlled by a reset check valve 69 normally closing said communication and urged to its cIosed-positionpy -a "spring El and the pressure of fluid from the reservoir in passage 54. A'fingeroperated plungerez is provided for unseating the valve "60 toallow equalization ofthe fluid pressures-onoppos'ite en'ds'of veilve'p'iston '52and consequent movement "of S'arrret'o its open'pos iti'on by spring55. Aspring E3 acting on plunger "62 is provided for moving same out of contact withvalvet'll toinsure seating of said valve. A valve '64 on plunger-62 is arranged to seat under action of spring -63 to normally prevent leakage of fluid under pressure :past 'said plunger.

The'wing flaps ("not shown) on'the'airplanemay be arranged for control by supply and release-of 'fluidunder pressure-through a pipe TB. For-controlling this supply and release of fluid under pressure to and frompipe 10a control valve device 1 l "of "any suitable structure such for example as disclosed in the cop'endingapplication of Rankin ZI. Bush and William 'l-L-Glass, Serial No.-400,'266, filed June 28, 1941, now issued as Patent No. 2;329;'742,dated September 21, 1-943, and assigned to the assignee of the "present application may be employed. The pipe 10 is connectedto'the control valve "device Tl as "are ,pipe "36 which is-"open to the main "reservoir?! and pipe 3| which connects "to the sump reservoir 32. The control 'v'alvedevice -H isoperative to establish communication between pipes 36 and 10 for supplying fluid under pressure from the main reservoir 'to the latter, and also operative to-closesaid com- -munication-and'open pipe '10 topipe 3| to release ffluidunder pressure from the flap control pipe 11 to the sump reservoir 32. With a normal or "maximum pressure of fluid-of around4'00 pounds pressure in the sump reservoir to a degree such as 1'00 pounds per square inch, wliich however=-will be quickly reduced =by-operation of the compres- "sor 3"0'-1 :orecompress this flufd back into the main reservoir ---3-7. It should here be --no-te'd that the 7 pressure of fluid in the sumpreservoir 32 and thus in the return pipe 33 will therefore vary from, for instance, 100 pounds per square inch to atmospheric pressure, and which latter pressure will also vary with the altitude of the airplane.

All fluid after use in the system to accomplish a desired operation, is released back to the sump reservoir 32 for recompression to the main reservoir 3! as will be hereinafter described. After the initial charging of the system with fluid under pressure, it will therefore be seen that fluid will be drawn from the atmosphere only to compensate for possible leakage in the system. Preferably all fluid taken from the atmosphere by way of check valve 35 in the inlet pipe 34 opening to the sump reservoir 32 will be drawnthrough any suitable dehydrating means, such as silica-j ell, in order to remove moisture therefrom, so that there will be a minimum of moisture in the system thus avoiding failure of any part of the system due to ice while operating in freezing temperatures.

.It will be noted that the system is a closed system with respect to the fluid pressure used, in that the once dehydrated fluid will be used over and overagain.

Description of speed regulating devices 5 The speed regulating device 5 associated with each engine I to 4 is substantially the same as fully disclosed in Patent No. 2,383,277 issued on August 21, 1945, to Roy R. Stevens, and assigned to the assignee of the present application. Briefly, this device comprises, as shown in Fig. 9, a casing '55 containing a flexible diaphragm I6 having at one side a control chamber 11. In the regulating devices 5 associated with engines I to' 4 respectively, the chambers 11 are connected through flexible conduits and pipes 18, 19, 88, and BI to the engineers speed control valve devices ll, I2, 53, and M respectively.

At the opposite side of diaphragm 16 in each of the regulating devices 5 is a chamber 82 containing a head 83 bearing against the diaphragm 16 and having a stem 84 extending through a suitable bore in the casing to the exterior thereof. 5

diaphragm 15 to their normal positions in which they are shown.

Outside of the casing of each regulating device 5, the end of stem 84 is connected by a pin 81 to a lever 88 intermediate the ends of said lever.

One end of this lever is pivotally connected by a pin 89 to one end of a link 99 the opposite end of which is connected by a pin 9| to the casing,

these connections between the casing and lever providing a floating fulcrum therefor. The 0pposite end of lever 88 is provided for connection with a speed controlling device such as the throttle control'lever 4C or the like on the respective engine in such a manner that when said lever 88 occupies the position shown, the engine will operate at a chosen low speed such as idling. Movement of the lever 88 from this idling position in a clockwise direction, as viewed in the drawing, effects the acceleration of the engine to a degree proportional to the extent of such move- .ment, and maximum speed of the engine being.

8 attained when the lever 88 occupies a position such as indicated by a dotted line 92 At one side of the stem 84 in each regulating device 5,. the casing containsa'flexible diaphragm 98 which is of relatively smallarea, such as onetenth of the areaof the main controlling diaphragm 1B. The diaphragm 93 has at one side a control chamber 94 and at the opposite side a chamber 95. A follower head 96 in chamber 95 bears against the diaphragm and is provided with a stem 91 which extends through a suitable bore in the casing to the exterior thereof. The casing has an annular groove open to this bore around the stem 91, and in this groove is a ring seal 98 having sealing contact with the casing and periphery of stem 91 for preventing leakage of fluid under pressure from chamber 95 past said stem to the atmosphere.

The end of the stem 91 outside of the casing is pivotally connected by a pin 99 to one end of a bell-crank I88 which at its knee is pivoted on a pin liJl carried by a bracket I02 extending from the casing. The other end of the bell-crank is pivotally connected to pin 81 connecting the diaphragm stem 84 to lever 88. These connections are such that the diaphragm 93, which will be hereinafter called a Vernier control diaphragm, is capable of free movementwith and in the direction of the main diaphragm stem 84 throughout full travel of said stem under deflection of diaphragm i8 which is limited by contact between the piston head 83 and a shoulder. I03 in the casing.

Pressure chambers 94 in the regulating devices 5 associated with engines I to 4 are connected respectively through flexible conduits and pipes M4, I85, 186, and ID! to the engineer's speed control valve devices ll, l2, I3, and [4, respectively. In each regulating device 5 diaphragm chambers 82 and 95 are connected together by a passage I08 and thence through a flexible conduit to the return pipe 33, whereby the two diaphragms are constantly subject, in said chambers, to the pressure of fluid in the sumpreservoir 32, the ring seals and 98 preventing leakage of fluid under pressure from said reservoir when the chambers are charged to a pressure in excess of that of the atmosphere. 7

When the diaphragm control chambers 11 and 94 are both open to the sump reservoir 32, in a 'manner which will be later described, the pressure of fluid on opposite sides of the two diaphragms will be the same since chambers 82 and at the opposite sides of the diaphragms are constantly open through return pipe 33 to the sump reservoir 32. Under this condition the pressure of spring 86 will therefore be effective to deflect the diaphragm 16 and urge the follower head 83 and stem 84 to the positions in which they are shown in Fig. 9. The stem 84 as it is thus moved positions the throttle control lever 88 and thereby the lever 48I in the engine idling position and the Vernier diaphragm 93 will occupy a position out of contact with the casing, as shown in .Fig. 9. I

tion will rock the control lever 88 and thereby lever 4M out of the idling position in which it is shown to a position for providing the desired increase in engine speed. If the pressure of fluid in diaphragm chamber 11 is then increased, a corresponding change in position of levers 88 and 4M will be effected so that an increase in the speed of the engine will occur. on the other hand, if the pressure of fluid in chamber TI is reduced, the levers 88 and lsi will operate to correspondingly reduce the speed of the engine. Maximum engine speed will be obtained when the lever 88 occupies a position such as indicated by the dotted line 92, and this position may be obtained when the pressure of fluid supplied to chamber TI is sufficient to deflect the diaphragm to the position in which the head cs contacts shoulder I03 in the casing.

When by operation of the pilots control valve device Ill fluid is suppied simultaneously to pressure chamber I? in all of the speed regulating devices 5 in a manner to be later described, it will be seen that the same pressure of fluid will be effective in each of the speed regulating devices 5 to provide simultanous and like adjustment of levers 88 and Ill and thereby of the speed of the several engines. Such like adjustments of levers 401 may not however provide the desired synchronous operation of the several engines due to variations such as before described, however, all of the engines may be brought into desired synchronism by slight adjustments of the lever 83 in one or more of the regulating devices with respect to the lever or levers in the other regulating devices. These slight adjustments may be obtained by supplying fluid under pressure to chamber 94 in the desired one or more regulating devices for acting on diaphragm 93 in opposition to pressure of fluid in chamber ll acting on the master control diaphragm 16'. By this arrangement the selected lever or levers 83 will be adjusted in accordance with the d-iiierential in control fluid pressures in chambers ll and 94 respectively on the two diaphragms 16 and Q3. Thus, if the speed of one engine or more than one engine is excessive with respect to the speed of another, such speed may be reduced to bring the engine or engines int'odesired synchronism with the other engine or engines by supplying the proper degree of fluid pressure to the Vernier diaphragm control chamber 94 for modifying the effect of pressure in chamber TI on the master diaphragm l6 and which will move the lever 88 in the direction to reduce the speed of the engine. By such adjustments of the regulating device 5 for one or more engines the speed of all engines may be brought into desired synchronism, as will now be apparent.

When the several regulating valve devices 5 are connected for simultaneous control from the pilots control valve device II} the adjustment of pressure of fluid in chamber at on the Vernier control diaphragm 93- in said devices to bring the engines intodesired synchronous operation is a function of the engineers control valve devices H to I 4 as controlled by the engineer, as will be later brought out.

Description 0 devices 6, 7, and 8 The construction of all. of these devices be identical, and as shown in Fig. 10' each may comprise a casing I I I3 containing a flexible diaphragm III having at one side a fluid pressure control chamber I I2 and at the opposite side a chamber I-t3 which is open to the return pipe 33 leading,

to the sump reservoir 32'. The chamber H3 contains a follower or head H4 bearing against the diaphragm and having a stem II 5 projecting through a suitable bore in the casing to the exterior thereof. The casing is provided with an annular groove encircling the stem I I5 within the bore for carrying a sealing ring H5 which bears against the casing and stem for preventing leakage of fluid under pressure from chamber H3 and thereby from the sump reservoir 32' to atmosphere along said stem. A spring ill in chamber H3 bears against the head II4 for urging said head and diaphragm I I I to their normal positions, shown in Fig. 20, when the pressure of fluid in control chamber H2 is the same as the pressure in chamber II 3. Outside of the casing the end of stem I I5 is connected by a pin M8 to a control lever I I9 intermediate its ends. One end of the lever is pivotally connected by a pin- I2il to a link. the opposite end of which is pivotally connected by a pin I22 to the casing.

In the operation of these devices when the pressure of fluid in control chamber M2 is substantially the same as that in chamber I I3 at the opposite side of diaphragm III, spring ill will hold the head H4 and diaphragm III in their normal position shown and thereby position the connected lever H9 in its normal position shown. When fluid is supplied. to control chamber M2 at a pressure exceeding the opposing pressure or fluid in. chamber I 33 plus that of spring ii? the diaphragm III will deflect to the left and move to a position corresponding to the diflerential in fluid pressures acting on the diaphragm and thus correspondingly position the lever H9 away from its normal position. An increase in the pressure of fluid in control. chamber M2 will cause a corresponding further movement of the lever MS! from its normal position, while a reduction in the pressure of fluid in chamber H2 will allow spring II! to return lever II9 toward its normal position to a degree corre-- sponding to such. reduction.

At each engine the levers i 9 in the regulating devices 6, I, and 8 are connected to levers 402, 403, and M25 whereby the richness of the fuel mixture, its temperature and the operation of the supercharger may be regulated in accordance with the adjustment of lovers IIS as just described.

Chambers H2 in the mixture regulating devices 6 associated with engines I to 4 are connected by pipes I23, I24, I25, and I26 to the engineer's mixture control valve devices It to I9, respectively.

Chambers II 2 in the temperature regulating devices I associated with engines I to 4 are connected. respectively by pipes I3I, I32, 533, and I34 to the engineers heat control valve devices 20 to 23.

Chambers I I2 in the blower regulating devices 8 associated with engines I to t are connected respectively by pipes I38, I39, MI], and IAI to the engineers blower control valve devices 24 to 21.

Description pilots control valve device 10 The pilots speed control valve device III comprises a casing containing an automatic or selflapping valve mechanism which for illustrative purposes only may comprise two spaced and axially aligned flexible diaphragms I41 and I48 of the same areas which are clamped around their marginal edges between two of the casing sec- 11 tions. The two diaphragms are connected for movement in unison by a stem I49 which extends through an opening in a shelf I50 extending from the easing into the space between the two diaphragms. A pressure chamber II is provided between the shelf I50 and diaphragm I41 while a pressure chamber I52 is provided at the opposite side of the shelf, these two chambers being in permanent communication through a passage I53 in said shelf. A coil spring I54 contained in chamber I5I has one end supported on the shelf I50 while its opposite end bears against a follower I55 which is secured to the stem I49,

said spring being arranged to oppose movement of the diaphragms in a downward direction from the position shown as viewed in the drawing. In this position of the diaphragm the spring I54 is substantially fully expanded.

The two pressure chambers I5I and I52 are arranged to be constantly supplied with fluid under pressure from either of the fluid pressure supply pipes 45 or 46 by way of a double check valve device I56 and a differential pressure regulating valve device I60.

The double check valve device I56 comprises a casing having a chamber to the opposite ends of which open the pipes 45 and 46. A double check valve I5I disposed in this chamber and subject on opposite ends to pressure of fluid in pipes 45 and 46, respectively, is arranged to control communication between said pipes and a passage I51 leading to the regulating valve device I60. With the check valve I6I in the position shown, it closes communication between pipe 46 and passage I51 and opens said passage to pipe 45 and said valve is constantly urged to this position by the pressure of a spring I59. It will thus be seen that with both the auxiliary and emergency reservoirs 39 and 44, respectively, charged with fluid at substantially the same pressure, fluid will be supplied from the auxiliary reservoir to passage I51 by way of pipe 45. In case, however, pipe 45 should become ruptured, the consequent reduction in pressure on the spring side of the check valve I 6I will allow emergency reservoir pressure acting on the opposite side to shift the check valve to its opposite position for, closing communication between passage I51 and pipe 45 and for opening said passage to the emergency reservoir supply pipe 46.

The pressure regulating valve device I60 comprises a fluid pressure supply valve I44 contained in a chamber I45 constantly supplied with fluid under pressure from the auxiliary reservoir or emergency reservoir by way of passage I51 and is provided for regulating flow of fluid from said chamber to a chamber I46 which is open at all times to pressure chambers I5I and I52 between the two diaphragms I41 and I 48. in chamber I45 acts on the supply valve for urging same to its closed position. Chamber I46 is provided at one side of a flexible diaphragm I81 which has its opposite side exposed to pressure in a chamber 2I1. Chamber 2I1 is in constant communication with the sump reservoir 32 by way of passage M8 and 2 I9, a chamber 240 below the diaphragm I48 and the return pipe 33.

The supply valve I44 has a fluted stem extending into chamber I46 provided at its end with a release valve 315 arranged to cooperate with a seat 316 provided centrally on the diaphragm I 81 for controlling communication between said chamber and chamber 2I1 and thus the sump reservoir 32. A spring 311 contained in chamber 2I1 bears at one end against the A spring I85 valve seat 316, while the opposite end is supported on a seat 313 carried on the end of an adjusting screw 319 screw threaded in the casing;

This screw is so adjusted as to cause spring 311 to exert a certain chosen pressure on the diain chamber 2 I1 acting on the diaphragm I81 will deflect same to open the fluid pressure supply valve I44 for allowing flow of fluid under pressure from passage I51 to chamber I46 and thence to chambers I5I and I 52 until the pressure of such fluid effective in chamber I46 on the diaphragm overcomes the opposing force of said spring and pressure of fluid in chamber 2". When this occurs, the pressure of fluid in chamber I46 acting on diaphragm I81 will deflect said diaphragm to permit closure of valve I44 and thus limit the pressure of fluid obtained in chambers I5I and I52 to a degree in excess of that acting in the sump reservoir 32 equal to the adjusted force of spring 311 on the diaphragm, regardless of the pressure of fluid in said sump reservoir.

The spring 311 may be so adjusted as to limit the pressure of fluid supplied to chambers I5I and I52 to a degree such as 150 pounds over that in the sump reservoir 32. Thus if the pressure of fluid in the sump reservoir is for instance 7 pounds, the regulating device I60 will supply fluid at 250 pounds pressure to'diaphragm chambers I5I and I52. On the other hand'if the pressure of fluid in the sump reservoir 32 is equal to that of the atmosphere, then the regulating device I66 will limit the pressure of fluid supplied to chambers I5I and I52 to pounds above atmospheric pressure. For any intermediate degree of pressure of fluid in the sump reservoir 32, the regulating device I60 will limit the pressure obtained in chambers I5I and I52 to a degree 150 pounds in excess of such pressure in the sump reservoir. In case the pressure offluid in the sump reservoir should be increased, such increase effective on the diaphragm I81 will cause deflection thereof to open the supply valve I44 to cause a like increase in pressure of fluid in chambers I46, I5I and I 52. On the other hand, a reduction in pressure of fluid in the sump reservoir 32 will permit the pressure in chamber I46 to 'deflect the diaphragm I81 out of seating engagement with the release valve 315 which will permit a reduction in pressure in chambers I46, I5I, and I52 by flow of fluid under pressure therefrom to chamber '2I2 and thence to the sump reservoir 32. When the pressure of fluid in chambers I46, I5I, and I52 is thus reduced according to the reduction in pressure in the sump reservoir 32, spring 311 will deflect the diaphragm I01 into seating engagement with the release valve 315 for preventing further reduction in pressure in chambers I46, I5I,and I52.

It will thus be seen that regardless of the pressure of fluid in the sump reservoir 32, the regulating valve device I60 will maintain fluid in chambers I46, I5I, and I52 at a pressure a chosen degree above that in the sump reservoir, such for example as 150 pounds above mentioned, and as governed by the adjustment of spring 311.

When fluid under pressure is being used from chambers I5I and I52 as will be later described the supply valve I44 may not seat as above described, but instead will move toward its seat for throttling the flow of fluid under pressure from chamber I45 to chamber I46 to such a degree as to just maintain the chosen degree of pressure in chambers I58 and II in excess of sump reservoir pressure. The valve I44 will actually seat only when no fluid is being drawn from chambers I5! and I52 and when said chain bers are charged with fluid at the pressure determined by the force of spring 311 and a stable sump reservoir pressure in chamber 2I1.

The only purpose of the novel regulating device I66 is to limit the diiferential of pressures obtainable on the diaphragms I41 and I48 to a tie-- gree which will prevent damage to same. It will be noted that diaphragm I48 is subject to the opposing pressures of fluid in chambers I5! and I52 on one side and in chamber 249 at the opposite side so that said diaphragm can never be subjected to a differential in pressures greater than limited by the regulating device I66. The diaphragm I41 is also subject to pressure of fluid in chambers I5I and I52 and the opposing pressure of fluid in a chamber I63 which at times is open to the sump reservoir 32 as will be later described, so that said diaphragm can therefore never be subjected to a differential in fluid pressures greater than provided by the pressure regulating device I60. If the pilots control valve device I6 were of a type in which the diaphragm or diaphragms could never be subjected to pressure of the fluid in the storage reservoirs, the reducing or regulating valve device I66 might be dispensed with.

Chamber I63 provided above the diaphragm I41 is connected through a port I64 to a passage I65. A sleeve-like bushing I66 is secured in the casing above diaphragm I41 and extends into the pressure chamber I63. A plunger I61 is mounted to slide in the bushing I66. The bushing I66 is provided with an annular recess encircling the plunger I61 and containing a ring seal I68 contacting the bushing and plunger for preventing leakage of fluid under pressure from chamber I63 past said plunger. The lower end of plunger I6? is provided with a valve seat for sealing engage-- ment by a release valve I69 having a fluted stem slidably mounted in a bore in said plunger. This bore extends. from the valve seat to a point above the upper end of sleeve I66 whereat it opens through a passage I69a to a chamber I19 which is connected by passages I62, I'II, H6, and 219 to chamber 24!] below the diaphragm I48 and thus to the return pipe 33. A spring I13 in the bore in plunger I61 bears against the stem of the release valve I69 to unseat same.

The release valve I69 is engaged by the end of a fluted stem projectin from a fluid pressure supply valve I14 which is contained in a chamber 1 I15 provided in the upper end of the diaphragm connecting stem I49. The chamber I15 is constantly supplied with fluid under pressure from pressure chamber I5! by way of bore I16 provided in the diaphragm connecting stem I49 and which bore contains a spring I11 acting on the supply valve for urging same to its closed position shown. Below the plunger I61 and withinthe bushing I66 is a chamber I18 which is open through one or more bores I19 to an annular chamber I86 encircling the bushing I66 and connected to one end of passage I66. The opposite end of passage I65 is connected to a cut-off valve device I1I which is arranged to. controlv com-- munication between said passage and a pilots; engine speedcontrol pipe I82.

An adjustable operating screw I63 is secured by screw-threaded engagement into the upper endof plunger I61. The plunger L61. is provided. around its upper. end with a; spring seat I96. An

initially powered coil spring I is interposed between the upper end of bushing I66 and spring seat I84 for constantly biasing the. plunger I6! in an upward direction.

An operating shaft I88 arranged at right angles to the axes of the two diaphragms extends through chamber I10 above the operating screw I83 and has its opposite ends journaled in bearings in the casing. Anintermediate portion of the shaft is journaled in a bearing provided in a wall I89 which separates chamber I-Iii from a chamber I96. The shaft I86 extends through an outer wall of chamber I19 and said wall is provided with an annular groove encirclingv said shaft and containin a ring seal I62 for preven ing leakage of fluid under pressure from chamber I16, which is open to the sump reservoir 32,v along said shaft to the atmosphere.

A cam I94 disposed in chamber I16 is secured to the shaft I88 for rotation therewith, the peripheral surface of said cam being arranged for contact with the regulating screw I63. A lever I95 for operation by the pilot is secured to the portion of shaft I88 projecting beyond the outer wall of chamber I18. This lever may, if desired be connected through the medium of link I96 and a rock shaft I91 to a similar lever arranged for operation. by the co-pilot of. the airplane, whereby either the pilot or co-pilot may operate the lever I95 torock the: shaft I88 and cam I94.

In Fig. 3 the pilots control lever I95 is shown in a position to be used for obtaining operation of; engines I to 4 at av chosen low or idling speed. The lever is movable from this position in a clockwise direction through a. zone indicated by the legend speed range for increasing the spec of the engines in accordance with the extent of movement away from the idling position shown, the maximum speed of the engines being obtainable in a position such as indicated by a dotted line bearing the numeral I98. The lever I95 is also movable in a counterclockwise direction from the idling position shown in Fig. 3 to a position i indicated by a dotted line I99, for reasons which will be later brought out.

With the pilots control lever I95 in the. engine. idling position as shown as well as between this position and the position indicated by the dotted line I 99 the cam I94 allows positioning of the regulating screw I83 and plunger I61 by spring I85 as shown in the drawing. In this position of plunger I61 the release valve I69 is opened by spring I13 and the fluid pressure supply valve I14 is closed by spring I11 so as to thereby open the engine speed control pipe I82 and chamber I63 above the diaphragm I41 past said release valve to chamber I16 containing the cam I66 and thus through the return pipe 35 to the sump reservoir 32. Under this condition the spring I66 acting on the diaphragm I4? is fully expanded.

If the pilot now moves the lever I66 from its engine idling position, in which it is shown, in a clockwise direction into the speed range zone.

' the cam I94 acts to move the regulating screw I63 and thereby the plunger I6? in a downward direction. The plunger I'E'I after a slight down-- Ward movement, seats against the release valve- I69-, then continued downward movement the supply valve I14, whereupon fluid under prev sure supplied to chamber I5-I' below the diaphragm I41 flows past said supply valve to chamber in thebushing I66 and thence through port I'iil said bushing to passage I65 and. from said passage through the cut-off valve device I8I to pipe E82.

At the same time fluid under pressure also flows from passage I65 through port I64 to chamber I63 above the diaphragm I41 and acts to deflect said diaphragm against the opposing force of spring I54 and pressure of fluid from the sump reservoir effective in chamber 246 on diaphragm I48. After a certain movement of the diaphragm I41 by pressure of fluid in chamber I63, dependent upon the extent of movement of the pilots control lever I95 out of its engine idling position and the consequent degree of movement of the supply valve I14 from the normal position shown, the stem I49 which moves with said diaphragm moves into seating contact with the supply valve I14 and thus cuts off further flow of fluid under pressure to pipe I82 and chamber I63 above said diaphragm, thereby limiting the pressure of fluid supplied to said pipe to a degree exceeding that in the sump reservoir 32 by an amount governed by the extent of movement of the control lever I95 out of its engine idling position shown.

If the pilot moves the lever I95 further in a clockwise direction, the supply valve I14 will be again unseated to allow further flow of fluid under pressure to pipe I82 and chamber I63 above the diaphragm I41. The diaphragm I41 will then again be deflected downwardly against spring I54 under this increase in fluid pressure until the supply valve I14 is again seated for closing off the supply of fluid under pressure to said pipe, thereby again limiting the pressure of fluid attained in said pipe in accordance with the new position of the pilots control lever I95. In case the control lever I95 is moved to the full speed position indicated by the dotted line I98, a maximum degree of pressure over that in the sump reservoir will be obtained in the speed control 7 pipe I82, as will be apparent.

Now in case the pilot moves the control lever I95 in a counterclockwise direction from the full speed position indicated by the dotted line I98 or from any position intermediate the full speed position and the idling position, the cam I54 operates to render the bias spring I85 effective to move the screw I83 and plunger I61 in an upward direction. This movement of the plunger I61 is relative to the release valve I69 due to the action of spring I13 on said valve whereupon the release valve is unseated for releasing fluid under pressure from the speed control pipe I82 and chamber I53 above the diaphragm I41 to the cam chamber I16 and thence to the sump reservoir 32. As the pressure of fluid in chamber I63 above the diaphragm I41 is thus reduced, spring I54 and sump reservoir pressure in chamber 246 acting on diaphragm I48 urges diaphragm I-4'I upwardly and this movement causes the spring I11 acting on the supply valve I14 to move the release valve I69 in an upward direction. In case the lever I95 is not fully returned to its engine idling position shown, then the release valve I69 will seat against the end of the plunger I61 when the pressure of fluid in pipe I82 and in chamber I63 becomes reduced to a degree depending upon the distance the control lever I95 is away from the engine idling position shown. However, in case the lever is returned to the engine idling position, then the plunger I 61 will be so positioned by spring I13 that the release valve I66 will not seat upon equalization of the fluid pressures in diaphragm chamber I63 and pipe I82 with that in the sump reservoir effective in diaphragm chamber 246 since when this occurs, the spring I54 will be in a fully expanded position.-

16 It will thus be seen that with the pilots con trol lever I in the engine idling position as shown, the pressure of' fluid in the speed control pipe I82 will be the same as that in the sump reservoir 32 while upon movement of said a lever in a clockwise direction as viewed in Fig; 3, out of idling-position or in the opposite diree tion toward idling position, the pressure of fluid obtained in pipe 582 will exceed that in the sump reservoir by an amount proportional to the dis tance said lever is away from its engine idling position.

As just mentioned, the pressure of fluid attained in pipe I82 with the pilots control'lever I95 out of idling position and in the speed range zone will exceed that in the sump reservoir by an amount corresponding to the lever position and this condition will always'be attained regardless of the pressure in the sump reservoir since the pressure in said reservoir is constantly effective in chamber 246 on diaphragm I48 and thus cooperative with the control spring 254 to limit the pressure of fluid in pipe I82. In other words, assuming that the pressure in the sump reservoir is that of the atmosphere, the pressure obtained in pipe I82 for a selected position of lever I65 out of idling position Will exceed that of the atmosphere or sump reservoir b an amount governed by the force of spring I54 plus atmospheric pressure in chamber 246 acting on diaphragm I48. If now the pressure in the sump reservoir is increased for any reason, such pressure acting on diaphragm I48 will deflect same to open the supply valve I14 and cause a corresponding increase in pressure in pipe i82 thus maintaining the same diirerential between the pressures in said pipe and in the sump reservoir as existed prior to the increase in pressure in the sump reservoir. On the other hand, if the pressure in the sump reservoir should become reduced, such reduction in pressure in chamber 246 on the diaphragm I48 will allow the pressure of fluidin chamber I63 acting on diaphragm I41 to deflect same downwardly and thereby unseat the release valve I69 for releasing fluid under pressure from the pipe I82 and chamber I63, and when the pressure in pipe I 82 and chamber I63 becomes reduced corresponding to the reduction in sump reservoir pressure in chamber I62, the spring I54 will deflect the diaphragms to close the release valve I 69 for thereby again limiting the pressure in pipe I82 in accordance with the reduction in sump reservoir pressure effective in chamber 246. In other words the same diflerential between the pressures in pipe I82 and sump reservoir will be obtained in any position of the pilots control lever I95 in the speed range zone, regardless of the pressure effective in the sump reservoir.

The cut-ofi valve device I8I arranged in the fluid flow connection between passage I65 and pipe I 82 may, with the exception of the omission of the reset structure, be structurally identical to the cut-off valve devices 46 and 48 to 56, hereinbefore described. The cut-off valve device I 8! therefore comprises a valve piston 52 for controlling communication between passage i65 and pipe I82. The valve piston is biased to the communication opening position by a spring 55. The chamber56 at the opposite side of the piston in this embodiment is connected to an operating volume 266 provided in the casing of the pilots control valve deViceMWhen fluid under pressure is supplied to pipe 82, this volume is charged with fluid under pressure from pas sage I65 by way of the restricted port 51. In case of breakage of pipe I82 when charged with fluid under pressure, the restricted port 51 acts to limit the release of fluid pressure from volume 200 so as to thereby maintain a suiflcient pressure in chamber 56 on the one side of the valve piston for moving said piston to its closed position against the force of spring 55 upon the release of fluid under pressure from the opposite side through said pipe. The cut-E valve device I8I is thus adapted to act in case of breakage of pipe I82 to prevent loss of fluid under pressure from either the auxiliary reservoir or emergency reservoir in case the operators control lever I95 should be moved to or be in a position in the speed range zone supplying fluid under pressure from said reservoir to passage I65.

In order to return the valve piston 52 in the cut-01f valve device IBI to its communication opening position shown in the drawing, as after repair of the broken pipe I82, the pilot need only move the control lever I95 back to its idling position for thereby releasing fluid under pressure from chamber 56 and the operating volume 200 to the sump reservoir 32. With the pressure in the sump reservoir equal substantially to that of the atmosphere due to operation of the compressor 30 and with the pressure of fluid in chamber 56 correspondingly reduced spring 55 will then move the valve piston 12 to its communication opening position in which it is shown.

The pilots control valve device I0 also embodies a transfer control valve device 20I comprising a poppet valve 202 contained in a chamber 23 which is constantly supplied with fluid under pressure from chamber II between the two diaphragms I41 and I48. This valve is provided for controlling communication between chamber 293 and a chamber 209 provided at one end of a bore 204 and which is open to a transfer control pipe 205 leading to the body I5 of the engineers control valve devices II to I4. A spring 293a in chamber 203 acts on the supply valve 202 for urging same to its seated position. A plunger 206 is slidably mounted in bore 204 and carries a poppet type release valve 201 arranged to seat on the plunger in a direction opposite to the seating of the supply valve 202, said valves having fluted stems extending in the direction of each other for contact in chamber 209. The casing is provided with an annular groove encircling the plunger 206 and containing a sealing ring 298 engaging the outer peripheral surface of the plunger for preventing leakage of fluid under pressure from chamber 209 to a chamber 2I0 at the opposite side of the plunger, the chamber 2I0 being in constant communication through passages I62, I1I, 2I9, and diaphragm chamber 240 with the return pipe 33 and thereby the sump reservoir 32. A spring 2I'I in chamber 209 acts on the plunger 206 for urging same in a direction away from the supply valve 202; a shoulder 2I5 being provided for contact with plunger 296 to limit movement thereof by spring 2| I.

The chamber 2I0 is separated from chamber I90 by a wall 2 I2 in which a plunger 2I3 is slidably mounted in axial alignment with the release valve 201 and having one end in contact therewith. A cam 2I6 disposed'in chamber Hit is secured. to the shaft I08 for rotation therewith and has its peripheral surface arranged for contact with the plunger 2I3. This cam is so designed that with the pilots control lever I95 in the idling position shown in Figs. 3 and 4 and in all positions to the right thereof in the speed range 18 zone the plunger 2 I3 will be displaced in a downward direction to an extent suflicient for seating the release valve 201 against the plunger 206 and for so positioning said plunger in its bore that the stems of the release valve 201 and supply valve 202 will be in contact with each other and the supply valve will be open.

Thus while the pilots control lever I is in the speed range zone for controlling the speed of engines I to 4 fluid under pressure will be supplied past the supply valve 202 to the transfer control pipe 205. When the pilots control lever I95 however is moved from its idling position to the position indicated by the dotted line I99, a recess 2I4 in the cam 2; allows the force of spring 2H to move plungers 206 and 2I3 in a direction away from the supply valve 202. plunger 206 thus moves until it contacts the stop 2E5 which allows closing of the supply valve 262 by the pressure of spring 203a. The recess 2I4 then allows further movement of plunger 2I3 by the release valve 201 under pressure of fluid from the transfer control pipe 205 to a position in which said valve is opened and releases fluid under pressure from said pipe to the sump reservoir 32.

Descriptionengineers speed control valve devices 11 to 14 As above described the engineers speed control valve devices II to I4 for controlling the speed of engines I to 4, respectively, are all structurally identical and are associated with the common housing I5. In the housing I5 are four passages 220, 22!, 222, and 223 which extend therethrough for connection with each of the valve devices I I to I4. The passage 220 is connected to the pilots speed control pipe I82. The passage 22I constituting a fluid pressure supply passage to the four valve devices II to Hand to pipe 65 by way of a passage 229 is connected to a pressure regulating valve device 224 which is mounted on one side of the housing I5 and which device carries a double check valve device 226 having connections with the auxiliary and emergency reservoir pipes 45 and 41. The passage 222 is connected to the transfer control pipe 205 leading to the pilots control valve device I0. The passage 223 is connected to the return pipe 33 leading to the sump reservoir 32.

The pressure regulating valve device 224 and double check valve device 226 are structurally and functionally identical to corresponding devices I60 and I56 associated with the pilots control valve device I0. While the same reference numerals have been applied in the drawings to the corresponding parts of these devices, a detailed description however is not necessary beyond mentioning that chamber 2 IT in the regulating device 224 is constantly open to the sump reservoir 32 in this embodiment by way of a passage 232 which opens to a passage 233 in the engineers speed control valve device II and which latter passage is open to the sump reservoir passage 223. It is desired to point out however that the pressure regulating valve device 224 and the double check valve device 226 cooperate to maintain in passage 22I fluid at a pressure a chosen degree in excess of that in the sump reservoir 32 regardless of the pressure of the fluid in the sump reservoir. The'pressure thus maintained in passage 22I is preferably substantially the same as provided in the pilots control valve device Iil by the regulat ng dev ce I T e two pressure regulating devices I60 and 224 are em- The control valve device a maximurn degree of pro- I e t n ainst loss eifli id tinders due o i br akaee. It de iredte eesi Poin es that e eg ating. alve. devise ,0 d 224 ar n e ui ed ith. eentr devic s s h asv emf p ov d or lustra ive Purpo s wh h mbody d eehreem that a some t me m ght other is b 'su ieet d ts t e d t uctive i er t e tv e n t e pressure nt e o ge r e rs an a t eslimig es veira E h o th agle ers speed n r lve C vices it to. [4. comprises a control transfer valve d ice 35!: and en ine speed contrel a v device 252. a c The ransfer va ve devise compr ses a: flexible die sh ee ev 2 3 i hav ngja o e i a chamber 2 which s nerma l een eet t ug pass s-e ass to m ssag Z12. transe ed by p pe 295 to the i e f e htiql alve device in. at the opp ite side of diaphragm 243 is a valve chamber 2% constantly supplied with fluid under pressure from-passage 22 I through a passage 241. A spring 248 in chamber 244 acts on the diaphragm ass, er i ie same the d r etieri oi va ve enamher-24.6. v

he valv eha iiber 24d conta n a. ide valv 2% whi h s meenteii e tween w spa d shew: ens lir rided on em Q; ne s em 2 5 which is ee i e ed at e se-end to a d a hr m 1 s wherebv me ement Qt the dia hra m n? ei he ne d e ti n the ether w l. cause co eeQn -ine; me em ntei: e-sl de v ve.

The diaphragm t-4t and: slide va v hav w oper tin 'positions namely a p o 's n in spee contro P si ion, shewin n h raw n n en ine rs n ine: teed; eent l p sition hich; m y be efin d b55- entee e en. e

' s em 1 nd t nii w nithe h i w n the pilots controllever LQQJs-in-theengineidling pos i s-i bew i is o in; anvp 1 to. the right th -e of. in; thef speed range Zone, th ebyfe ng o era on at thetr r ns: fer device. 2&4. to suppl g under pressure. to pipe 285, this pressure will be effective in chamber; 344

at one; side, of the diaphragm- 243 and render spring 2 48, efiective to. niove the diaphragm 29:3 an Iide a v 9. he o s peed co t ol DQsition shown in Fig 5, However, vwhen the iilotfsfiOntrolleve r l-9,5,=i;s moved to the position ndicated by he dotted lin 1 9 d t control transfer; valve device 241. therefore operates to e ase: uid.- under n es urt r m p p teeto the. sump resenvoin 32; the; corresponding release of fluid; und l fl fil fi from the d aph a m chamber; 244; renders: the pressure of fluid valve ehembere fit ve- 0 ove he iaphragm' and-thereby the; slide valve zdse to the enginfielfis' control, position defined by; engagement of stem Z5QWifll the stop;l. It'W-ill; be noted that with diaehresm amb r 4 ope eu n resf qilfl; hey ia-n ra m 43? i pr ted a ainst ptllter ince the pr sure-1701f: uid: in chamber Mot-at. thepppositqside of-the diaphragm isiunder heee ;of z sulatin rva ve device 2% Bas s 22;!Lin the housing; which:passage is connec -to the p11 sesheed-icontrol pipe: I 82;,

videdwith; a cavity: 25!? arranged in. the pilots In the engineers speed control valve device it the nassaee255 is connected to pipe is leading to diaphragm chamber" in speed regulating device 5 associated with engine-L The passage 255 in the other engineers speed control valve devices l2 to [4 are connected respectively by pipes 18, 801, and 8! to the. speed regulating devicesv 5 associated with en ines 2, 3,. and 4; With the s idealves 249' of all of. the engineers speed ntrol valve devices to. 14; in thepilots control positi n, as shown in Fig. 5., and which as above will).

described will be assumed with the pilots control lever in. its, engine. idling position or in any position in the speed range? zone, it will be seen that the pilot by movement, of lever I95 into said zone. may cause. simultaneous: operation of all of, the. speed regulating. devices a and thus simultaneous adjustment. or the speed of the several engines; Whenhowever the. diaphragm 2.143, and. slide; valve 24:91: inthe engineers speed QntlfQl Valve devices'l l .to .:k4 occupy the ensineers, control position defined by contact: between stem 250 and stop 25L, and which position is Obtained upon moizemenit, of thepilots control lev r to he positions indicated by line: 19a communication between-thee DilQfls speed control pipe I82 andthe severali sneedregulating devices 5 by W y Of; Gait/Titles; 2 541m the; slidevvalves. 24 9: islbroken to thereby revent centred of engine speed y h P l t. '7. .1 '9

E ch: of; the; en ineers: sneedircontizol; valve devices I. to; It further comprisesha. flexible diaphragm 2.55! ela-mpedi around its. margin between e housin 11532 16; a cover member 25s.: This d phra mihas at onegsi'de ache-miner 21593 111; con: stant cqmmunicatipnq with the sump reservoir hr gh-v the passage Zfifirhereinbrzfora mentioned; and at. t e- Qpposite side a chamber 2st which is connected: by; a passage: 252'.- to. the seat of slide valve 249. A tolldwerjml; isrsecured' centrally to) diaphragm En land: has; a passage 282 for connectin chamher 'lfilli to chamber 259. In chamber lfimthesfzollowen-ilill' is provided around the end of: passage 262 with aivalve-seat'arranged for engagement a. release valve 253 which 7 is provided on-"the end of a; fiuted=stem= project'- ing froma supplyvalve 264 f contained in a chamber 265' which is constantly supplied with fluidunder pressure fronr'the supply passage 221 past a check valve The-check valve. 2% seats oppositely-to jthe's pply valve 26 i and a spring 7 26 1* containedinfchambelf 2'65" hears at opposite ends 01i said; valves for urging them to their seated or: closed-- pQSiti'Q STaS' shown. h

Above chamber 25.8"the cQyer: 2581's provided with a bore open to saidihchamber and aXially aligned with the diaphriaignfiz liilrand; containing a lunger 26 ;l e ween which and the diaphragm follower 2161;"is interposedya; control. spring. 218. The plunger Z63; has, an operating; stem. 2H slidably mounted, in',aborevin-coverri da, and ext-emling nt a hamhen- 212; in said. cover. The

cover is. provided; with; an. annular grooveen:- circling, plunger 21], and containing a sealing ring 213. contacting the neribheraisurface of the plunger for: preventing; leakage'ot fluid; underpressure-from; chamber 259-; which is open to the; sump reservoir %;113117011331'10617 2:1 2:

Chamber: 212:. contains .a; cam 2114 which is mounted on an opeiiatingishafti 21$ with its peripheral surface in: contact unththe end; of plunger- ZHis 1% leverzfwiis seeured to-th-e shaft r 21 215 for turning same and the cam 214 relative to the plunger 21!.

In each of the engineers speed control devices H to 14 the passage 252 connecting chamber 260 below the diaphragm 251 to the seat of the transfer slide valve 249 is connected, with said slide valve in the pilots control position shown in the drawing by a cavity 211 in said slide valve to a passage 268 which in turn is connected by pipe 194, I95, 196, or N11 to the Vernier diaphragm chamber 94 in the respective regulating device 5. In the engineers control position of slide valves 249, the passages 268 are disconnected from passages 252 and the latter are connected by cavities 211 in said slide Valves to passages 255 which are connected to the master diaphragm control chambers 11 in the speed regulating devices 5.

It will thus be seen that in the pilots control position of slide valves 249, the master diaphragm chambers 11 in all of the regulating devices are connected to the pilots control valve device l9 so that the pilot may control the pressure therein, as previously described, while the vernier diaphragm control chamber 94 in the regulating devices 5 associated with engines I to 4 are connected to chambers 260 in the engineers speed control valve devices H to l4, respectively. In the engineers control position of the slide valves 249 the regulating devices 5 are disconnected from the pilots control valve device 19, and the master control chambers 11 in said devices associated with engines I to 4 are connected to chambers 269 in the engineers speed control valve devices H to l4, respectively.

When the lever 216 and cam 214 in each of the engineers speed control valve devices H to 14 are in the positions shown in the drawing, the plunger 269 will assume the position shown for relieving pressure of spring 219 on diaphragm 251 so that said diaphragm may assume the position shown for opening communication past the release valve 263. It will thus be seen that if the control levers 216 of the engineer's speed control valve devices II to 14 are in the positions shown, the Vernier diaphragm control chambers 94 in all of the speed regulating devices 5 will be open to the sump reservoir 32 when the transfer slide valves 249 is in the pilots control position shown. 249 thus positioned the engineer may operate lever 219 of any one of the speed control valve devices II to I4 to supply fluid at any desired degree of pressure to the respective Vernier diaphragm chamber 94 for thereby modifying the effect of fluid pressure provided in the master diaphragm chamber 16 of the respective speed regulating device by the pilots operation of lever i95, as will now be described.

Let it be assumed that the engineer desires to supply fluid under pressure to the Vernier diaphragm control chamber 94 in the speed regulating valve device 5 associated with engine I. To accomplish this end, he moves the control lever 219 of the control valve device I I out of the position shown in Fig. 5 in a clockwise direction and thereby actuates cam 214 to move the plungers 211 and 269 in the direction of diaphragm 251. This movement of the plungers acts to compress spring 219 the force of which acting on the diaphragm follower 26I moves same into seating contact with the release valve 263 .rollowmg which further movement acts through said release valve to unseat the supply valve 264. When the supply valve 264 is thus opened, fluid With the slide valves i 22 under pressure will flow from chamber 265 to diaphragm chamber 269 and thence through passage 252, cavity 211 in the transfer slide valve 249 and passage 268 to pipe- I04 and thence to the Vernier diaphragm control chamber 94 in the respective speed regulating valve device 5. When the pressure of fluid is thus increased in diaphragm chamber 269 in the engineers speed regulating valve device II and thereby in the Vernier diaphragm control chamber 94 of. the

speed regulating valve device 5 to a degree which overcomes sump reservoir pressure in chamber 259 plus the control force of spring 216, the diaphragm 251 deflects in an upward direction which allows sprin 261 to seat the supply valve 264 and cut on further flow of fluid under pressure tochamber 269 and the respective Vernier diaphragm control chamber 94. The pressure of fluid obtained in the Vernier diaphragm control chamber 94 in excess of opposing sump reservoir pressure in chamber 95 is thus limited by the degree of compression of control spring 219 which in turn is governed by the extent of movement of lever 216 out of its normal position shown in Fig. 5. If now the engineer desires to increase the pressure of fluid in the Vernier diaphragm control chamber 94, the respective control lever 216 may be moved further in a clockwise direction as viewed in Fig. 5 and a corresponding increase in pressure will occur in an evident manner. On the other hand if it is desired to reduce the pressure of fluid in the Vernier diaphragm chamber 94, the lever 216 may be moved in the opposite direction to reduce the pressure of spring 219 on the diaphragm 251. Upon such a reduction in spring pressure, the pressure of fluid in chamber 269 will deflect the diaphragm 251 out of engagement with the release valve 263 and thus permit the pressure of fluid in said chamber and in the connected vernier diaphragm chamber 94 to reduce by flow of fluid to chamber 259 and thence to the sump reservoir 32. If the lever 219 is still out of its normal position shown, the pressure in chamber 259 and connected Vernier diaphragm chamber 94 will reduce as just described until the force of sprin 216 predominates and which will then deflect the diaphragm back into contact with the release valve 263 and thereby limit the reduction in pressure in said chambers in accordance with the position of lever 216. If the lever is returned to its normal position shown, a complete release of fluid under pressure from chamber 269 and the connected Vernier diaphragm chamber 94 will occur or such pressure will reduce to equalization with that in the sump reservoir. It will thus be seen that any desired pressure of fluid in excess of that acting in the sump reservoir 32 may be provided in chamber 269 and the connected Vernier diaphragm chamber 94 by the proper positioning of lever 219.

It will be readily apparent that since the pressure of fluid in the sump reservoir 32 coacts in chamber 259 on diaphragm 215 with the force of spring 219, the pressure of fluid supplied to chamber 250 and the connected Vernier diaphragm chamber 94 will exceed that in the sump reservoir by a degree governed by said spring regardless of the pressure in said reservoir, and it will be further apparent that since sump reservoir pressure in chamber 95 opposes the pressure of fluid in the Vernier diaphragm chamber 94 in the regulating device 5, said deyice will be adjusted in accordance with the position of the engineers control lever 216 regardmeson that the pilot may operate lever I95 to supply fluid to the master control chambers 1! in the several regulating devices 8 to effect simultane ous adjustment of said devices to adjust the speed of the engines I to 4. However in the event that all of the engines do not operate in the do sired synchronism in response to this operation of the pilots control lever I95, and as may be determined by the engineer at his station through the observation of suitable gases or. other indicating devices, the engineer may then bring the engine or engines which are not prop erly operating, into the desired synchronism by operation of the lever or levers 216 of the respective speed control devices it, I2. .13., or 114 to supply fluid to the Vernier diaphragm control'chamber 94 in the respective regulating device 5. The fluid thus supplied to chamber 194.

in the one or more regulating devices will modsure'fromsaid reservoir will flow to piston chain ber 28! to thereby act on the piston 282 and move same against the pressure of spring 286. This movement 'of'piston 282 causes contact be.- tween the end of stem 283 and shoulder 285cm the respective earn 214 and if the lever 216 is out of its normal position shown 'said piston then acts to move said lever toits'normal position. Thus, if-any of the levers-216 are out of their normal position at the time "the pilot transfers the con.- trolof'spee'd of the engines to the engineer, such lever or levers will be:returned to normal positify the effect of the fluid pressure in chamber tion oi'sl-ide valve .249 a cavity 12:79 "thereinis provided for connecting this charged reservoir 218 :to a passage 28E) which leads to .a chamber an provided in the cover .258 at one side of a piston 282. The piston .282 has a stem 283 projecting through a chamber 284 at the opposite side of the piston into operative alignment with aishouldef 235 provided on the .cam 2:14. AspringtZBfi :in chamber 284 .acts on'the piston 282 for urging same to a normal position, as shown :in Fig. 15, whenchamber-Zti iszvoid of :fluid pressure. =the piston'282 :andzstem 283 in this normal'posizt'ion the end of the stem is so spaced'fromshoulrder 285 .on cam 214 .as to permit movement of :the lever 271i from the position in which it is shown through its full travel toa sposition such as indicated by dotted line 2.81,.so-asto thereby in no way interfere with operation .of itheyengtneers control lever 218 .to vary :the pressure of iiuid as desired in the :vernier diaphragm rcontrol chambers; of the respectivere'gulating iv-alve device 5 as hereinbefore described.

If the {pilot desires'to transfer the control :of (speed of all-engines I to-4 to the engineer, she -moves the lever I95 of his control device :11! tto .the position indicated by the clotted line 5139 and go (cause undesired aggglergfiqn m this oausesoperation of the control transiervalve .device 2.0l to release fluid under pressure from pipe 205 and-thereby from diaphragm lchambers zdiinthe'several engineers control valve-devices .l-l to Hi. Upon thiszreleaseof-fluid under pressure 5 .from diaphragm chambersiflflithe Opposing-pres- .sure .of fluid in valve chambers 3.4.6 :deflect :the :diaphragms 24:3 downwardly "and :move :the :slide .valves 249 to the .engineers :control :positiondetion by operation ofzthe respective piston or pistons 282. When the-pistons 282 complete their strokes under the influence of the pressure of fluid in chamber ZEIfcha-mbers 28.1 are opened to the atmosphere through a release port 28"? through which fluid under pressure is promptly dissipated 'fromnsaid chambers and thereby the volumes 2'18, whereuponsprings 285 return said pistonsand the stems 283 to their normal posi; tion as shown. r

When the pilot causesloperation of thecontrol Y transfer valve devices 24! to transfer the control of speed of the engines to theen-gineer, the move: ment of the slide valves 249110 the engineers control position disconnects passages 255 :from the pilots speed .control pipe 2 and connects said passages through'cavities 2:15 .in said valves to passages 252 leading to chambers 260 in "the engineers speed control valve devices, passages 268 connected with the verniencontifo'l diaphhagam chambers 9:2 in the-regulating devices 5 being lapped by the slide valves under this cond'tioi as previously described. Each of the .engineeris speedccntrol devices M to M is thereby rendered effective to control the pressure of fluid nhamr .ber 1? ion :the master .control diaphragm of the regulating .device .5 associated with the respective engines, whereby the engineer -,r r ay or regulate the speed .of the en ines 1iIidi-tiic1ually. .Since under :this condition the zrnaster diaphra m 16in the regulatingdev-ices .5 is subjected pressure of luid supplied by the en ines trol ,devices .I I itO i! .3, the same ran e of maria. in engine speed is provided fort-as whcnsuch .c-QIL- trol .wasunder the jurisdiction of the pilot,

The purpose .of the operation of pistons 1318. upon movement .of transfer slide -.val-.ves its 1 a :the -pilots-.control positions .to the en ine rs. :"bZOl positions is to heet movement .of an 1 1 r :Zl'dto its normal position in :case; it )hlitd 1 i ously'been adjusted out normal po ion i421 "supplying fluid {under ipressuresto thexi' w gtiilfi wern iertdiaphragniroontrol ch mber 94, :By fl hg fi moving the lever .216 backits) normal position he :fl d pressure-supplied y theiresnectivc .derice priorito such-m vement can not become fiective in chamber 7'! of the regulating ,de l

engine upon the-transfer ;of [con rol pilot to the engineer. I

The pilot :may, at will, takeiback the cont-m :of speed .of engines to Jl by moving seventh:

:transfer. slide valves 249 :to return no the :pilotis 'control position in which V is :shown thus proavidi-ng for the control of speed of .all engines :fined by contactbetween :the stems 50.;and :the :70 3170.1, asp-a u'nihfbyi-the pilgt amygrnmr contrglgf :stops:2.5l as hereinbeforeiiescribcd. in'lthisengineers :control position not each slide volve $41 .the reservoir :or :volume 3218 previously .icharged .with fluid under ;pressure .isconnected to rcavity .215 in said slide valve ithatifiuidmnderqores- 31 5 tcontrol communication through i passage'gzss 2-bereach engine.individuallyrhysthe-eengineer.asabove cdescribed. I V

:Inueach l of the .engineerfs .speed control valve .devices .:l [to HI a a plug waive 28,8 sis-provided to tween the control transfer passage 222 and the respective diaphragm chamber 244. Each of these valves has two positions and is movable to either of said positions by an operating handle 289. With the handle in the position shown in Figs. 1 and 5 the valve 288 establishes communication between the respective diaphragm chamber 244 and the control transfer pipe 205 which provided for control of the diaphragm 243 and slide valve 248 from the pilots control valve device l in the manner above described. When, however the handle 289 is moved to its other position indicated by a dotted line bearing the reference numeral 290, the valve 288 is operated to close communication between diaphragm chamber 244 and pipe 205, and said chamber is connected to the sump reservoir passage 233 for thereby releasing fluid under pressure from said chamber to said reservoir to allow movement of the diaphragm 243 and slide valve 240 to the engineers control position.

The handles 289 will normally be carried in the position shown in the drawing in order that the apparatus will operate as hereinbefore described. In case trouble should develop in one engine or another, however while the engines are under the control of the pilot, the engineer may move the respective handle or handles 289 to the position indicated by line 290 for thereby removing control of the respective engine or engines from the pilot and transferring such control to the engineer who can then stop the engine or engines, if such is desired or necessary. If, however, the engineer is able to correct the difiiculty, he may then transfer the control of the engine or engines back to the pilot by turning the respective lever or levers 289 back to the position in which they are shown in the drawing.

A cut-off valve device 29l is secured to the housing I of the engineers control valve devices H to I4 in the connection to each of the pipes connected to the several speed regulating devices 5. These cut-off valve devices may be identical in construction and operation to the cut-off valve device 18! associated with the pilots control valve device and each is provided to operate in case of breakage of the respective pipe to prevent loss of fluid under pressure through said pipe to atmosphere.

As above described, the pressure of fluid supplied by each of the engineers speed control valve devices H to M to diaphragm chamber 260 and by the pilots control valve device [0 to the speed control pipe I82, for controlling operation of the respective regulating valve device 5 will vary not only in accordance with the position of the respective control levers 216 and I95, but also in accordance with the pressure of fluid in the sump reservoir 32. The diaphragms in the speed regulating devices 5, which are subjected to pressure of fluid supplied by operation of one or another of the engineers speed control devices or by the pilots control valve device [0, are also subject to the opposing pressure of fluid in the sump reservoir 32, so that the effect of pressure from the sump reservoir in the engineers and pilots speed control valve devices is oil-set by its corresponding eficct in the regulating devices 5 and therefore has no effect upon adjustment of said regulating devices in accordance with selected posi tioning of the operating levers I95 and 2116.

From the above description, it will now be seen that the pilots control valve device [0 provides for control by the pilot of the speed of all of the engines in one bank in unisonor simultaneously iii) as desired during flight. With the engines thus under control of the pilot, the engineer cannot interfere in any way with such control except to make minor or Vernier adjustments of the speed regulating devices 5 individually for the purpose of synchronizing one engine with another. In case of difliculty with an engine the engineer may, however, annul the control of that engine by the pilot and subsequently return control to the pilot in case the difficulty is overcome.

It will also be noted that the pilot can, at will, take over the control of all engines, and can, at will, transfer the control to the engineer. When the engines are placed under the control of the engineer, he may regulate the speed of the engines individually as desired, but there is no Vernier adjustment of the engine speed under such control.

Description-engi1ieers mixture heat and blower control valve devices 16 to 27 These valve devices are embodied in the common housing 28 as above mentioned to which are connected the return pipe 33 from the sump reservoir 32, and the fluid pressure supply pipe from body l5 of the engineers speed control valve devices H to 14, the latter pipe being constantly supplied with fluid under pressure from the pressure regulating valve device 223. The housing 23 is provided with a passage 296 connected to the return or sump reservoir pipe 33 and having branches which will hereinafter be described leading to each of the control valve devices IE to 21. The housing 28 also has a passage 29'! connected to the supply pipe 65 and provided with branches for supplying fluid under pressure to each of the control valve devices [6 to 21.

Each of the mixture control valve devices It to l9 may be identical-in structure and operation; the valve device [6 being shown in section in Fig. 8 for illustrating the structures.

Referring to Fig. 8, the valve device 16 comprises a flexible diaphragm 298 clamped between the housing 28 and a cover 299 and having at one side a chamber 390 open through a cut-off valve device 39!, like the cut-off valve device I81 before described, to pipe I23 leading to the mixture regulating valve device 5 at the engine I. At the opposite side of diaphragm 298 is a chamber 302 which is open'through a passage 303 in the cover 299 and a passage 304 in the housing to passage 295 which is connected to the return pipe 33. A seat member 305 is secured to the diaphragm 298 at its center and is provided with an axial bore 301 for connecting chamber 300 to chamber 302. A release valve 300 provided in chamber 300 is arranged to cooperate with the seat member 335 for closing communication through the bore 301 and thereby between chambers 300 and 302. This valve is provided on the end of the fluted stem of a supply valve 308 contained in a chamber 399 which is constantly supplied with fluid under pressure from the supply passage 291 by way of a branch passage 309a and past a check valve 3l0 contained in chamber 309. A spring 3| I is interposed between the supply valve 308 and check valve 369 for urging same in opposite directions to their seated positions shown.

The cover 299 has a bore open to chamber 392 and containing a plunger 3l2 which is mounted to slide therein. A control spring 313 is interposed between and bears at opposite ends against the plunger Si?! and the seat member 305 on the diaphragm 298. The plunger 3l2 has an operating stem 3 M extending through a wall in the cas- 27 r 7 inginto a chamber ,315, asealing ring 322 being secured in this wall around and contacting said stem 'for preventing leakage of fluid under pressure from the sump chamber 302 to chamber 3l5. In chamber M5 the stem3l4 is engaged by the peripheryof a cam 316 which is secured to turn with a shaft 3I1 to which an Operating lever I21 is secured.

With the lever l 21' in the position shown in Fig. 8, the cam 3I6 is positioned "to allow suchexpansionof spring 3I2 as to permit deflection of dia phragm 298 out of seating engagement with the release valve 386 so as to thereby connect chamber H2 in the mixture control valve device 6 associated with engine I to the return pipe 33 by way of pipe I 23 and past said release valve. Under this conditionthe supplyvaive 308 is seated by spring 3H. If the operator'now moves the handle I21 in a counterclockwise direction, as

viewecl in Fig. 8, from the position shown, the

cam 3H5 will be operatedto move the plunger 3I2 in the direction of diaphragm 298 .for thereby increasing the force ofspring 3123 on said diaphragm. This increase pressureof spring 313 on diaphragm 298 will deflect same first into contact with the release valve 306 and then act through said valve to open the supply valve 308 for thereby supplying fluid under pressure from the supply pipe 65 to diaphragm chamber 300 and thence through :pipe I 23 to diaphragm chamber H2 in the respective mixture control valve device '3 Fluid will thus be supplied to the mixture 7 regulating device 3 until the. pressure thereof acting in diaphragm chamber becomes suflicient to deflect the diaphragm against the opposing will deflect upwardly to allow seating of the supply valve 388 for thus limiting the pressure of fluid attained in the mixture regulating device 6 pressure of spring M3 and of fluid in chamber V 392 which is open to the sump reservoir 32, and

when this condition is attained, diaphragm 298 in accordance with the pressure of the control springtlli. in turn governed by the position of lever I21 away from its normal position shown. Further movement of the lever I21 in a directiovn away from its normal position will causea corresponding increase in pressure of fluid in pipe I23 and thereby in diaphragm chamber H2 or the mixture control device 6, whilemovement of lever !21 in the opposite direction resulting in a reduction in force of the control spring 3I3, will result in the diaphragm being deflected out of contact with the release valve 306 bythelpressu re of fluid in chamber 300. Fluidunderlpressure' will then he released from diaphragm chamber I I2 in the mixture regulating device 6 until the pressure insaid chamber and inlchamber 300 is reduced to a sufiicient de ree below the opposing pressure on the dianhra gm, that said opposing pressure will mo e said diaphra m back into contact with the release valve 305 for thereby again limitin the pressure of fluid acting in the mixture regulatingdevice 5: in accordance with the position of the control lever l21. Return of lever I21 to its normal position will allow substantial full expan 'sion of spring 313 so that the diaphra m 298 may f move to and then remain in the'position shown in the drawing toprovide for equalization of the fluid pressure in chamber H2 of the respective V regulating device 6 into the sump reservoir 32. I

It will now be seen that therposition of lever I21 predetermines the pressure of fluid in excess of that in the sump reservoir-32 provided'in diahragm chamber I I2 oi the mixture regulating device 6.

taining one of these four positions, while the provision of three dififerent degrees of .fluid pressure in chamber H2 in; excess of the pressure of fluid in the sump'reservoir 32 willprovide for obtaining the'other three positions of lever H9. 7 To provide'these three-difierentdegrees of fluid pressure in chamber H2 of the resulatingdevices 6, the'lever I21 in each of the mixture control valve devices It to l9 may therefore have, outside of th normal position in which the lever is shown, threeother positions such as indicated by dot and dash lines 380, 38!, and 382. Movement of the lever I21 to any one of these three 7 positions or to its normal position will therefore cause corresponding positioning of lever I i-91in 'the respective regulating device E as will now be SEER. 7

Each of the engineersmixture control valve devices l1, I8, and I5 operates in the same mannor as the control valve device I6 for controlling operation of the respective'mixture regulatin devices Eat the different engines. It will thus be seen that the fuel mixture to each engine can be individually a justed by" the engineer to provide desired operation "Ea-ch of the engineers heat control valve devices 26 to 23 is identical in construction tothe mixture control valve devices 6 just described,

and the same reference numerals have been pplied to the corresponding parts except for the control lever which has been designatedby the numeral 135. As shown in Fig. 7 the heat con trol' devices 20 to 23are lconnected with the'fluid pressure supply passage 291 through passages 319, l and to the sump reservoir passa e 5 through passages 32a, and each is also; connected through a control passage '32I and a cut-01 T valve device 323; like the cut-off valve device I8I alcove described, to the respective pipe; I3I, I32, I33, or I34 tothe heat regulating devices 1.

It will be apparent without detailed description that with lever 1350f each of the heat control valve devices 20 to 23 in the normal position shown in Figs. 1 and 7, diaphragm chamber H2 inthe respective heat regulating device 1 will be open to the sump reservoir so that lever H9 of said regulating device may assume the position shown in Fig. 1. 'Movement of the lever I35 of the heat'c ontrol device Zllto 23 out of the normal position will provide fluid in the diaphragm chamber H2 of the respective regulating devices 7 1 at a -pressure corresponding to the degree of such movement; the maximum pressure :being attained with the lever I35 in a position indicated in Figs. 1 and 7 by the dot and dash line bearing the numeral 385 to cause corresponding positioning of lever H9 of the regulating device 1.

7 An intermediate positioning of the lever I35 will result in corresponding positioning of the respective lever H9 of the heat regulating device 1,

' as will be seen.

Each of the engineers blower control valve de- Vices 24 to 21 comprises ajcover 325 secured to the housing 28. 7 ing 28 has a chamber 326 which is constantly suppliedwith fluid under pressure from the supply passage 29'! by Way Of a branch passage 321 Under'the cover 325 the hone-' and past a check valve 328 contained in said chamber. The chamber 326 also contains a supply valve 329 for controlling flow of fluid under pressure from said chamber to a chamber 339 provided partly in the housing 28 and partly in the cover 325, the chamber 339 being connected through a passage 33! and a cut-off valve device 332, like the cut-off valve device 39! to pipe I38, I39, I40, or I4! leading to the respective blower regulating device 8. A sleeve 323 is slidably mounted in a bore in the cover 325 in axial alignment with the supply valve 329 and carries a release valve 324 arranged opposite to the supply valve 329 in a chamber 333 which is connected by a passage 334 to passage 293 leading to return pipe 33. A spring 335 in chamber 323 bears against the check valve 328 and supply valve 329 for urging said valves to their closed positions. A spring 336 in chamber 330 bears against the sleeve 33! for urging same in the direction of the release valve 333. Movement of the sleeve 33! in this direction is limited by engagement with a stop 331. The cover 325 is provided with a groove encircling sleeve 323 and containing a ring seal 385 which contacts said sleeve to prevent leakage of fluid under pressure from chamber 33!) to chamber 333 which is open to the sump reservoir 32.

A plunger 338 is slidably mounted in the cover with one end arranged to engage the release valve 324 while the opposite end extends into a chamber 339 this plunger being encircled by a ring seal 343 for preventing leakage of fluid under pressure from chamber 333 to chamber 339. In chamber 339 the endof plunger338 engages the peripheral surface of a cam 34! which is secured to turn with a shaft 342 to which is connected a lever I42.

With the lever I42 in the position shown in the drawing the sleeve 323 will-be urged by spring 336 into contact with stop 33'! to allow seating of the supply valve 329 under the action of spring 335 and which also allows opening of release valve 33? by pressure of fluid from chamber H2 in the respective regulating device 8, which pressure is effective in a chamber 339, whereby the pressure of fluid in chamber I I2 may reduce past said release valve into the sump reservoir 32. Y

The lever I42 is movable from the position just described to a position indicated by a dot and dash line 386; and upon such movement'the cam 3 1i operates to move the plunger 338 in the direction of the supply valve 329. The initial movement of plunger 338 seats the release valve 324 against sleeve 323 in case it is not already seated, w

and then further movement causes said valve to act to move the sleeve 323 against spring 335 bringing the stem of the release valve 324 into contact with that of the supply valve 329, so that the further movement of plunger 338 upon movement of the lever I42 to the position indicated by line 389 will then unseat the supply valve 329. Fluid under pressure will then flow past the supply valve to passage 33! and thence to diaphragm chamber H2 in the respective blower regulating device 8 to therein act on the diaphragm II! .to deflect same and move the lever I I9 thereof from the position shown to another desired operating position. When the operator desires to return the lever II9 of the blower regulating device 8 to its normal position shown, he returns the lever 42 to the position shown in Fig. 6 to allow release of fluid under pressure from diaphragm chamber H2 to the sump reservoir. It will thus be seen that by operation of one or more of the engineers 30 blower control valve devices 24 to 2'! the operator may cause individual operation of the respective blower regulating valve devices 8.

It will be noted that the blower control valve devices 24 to 21 are not self-lapping like the other engineers and pilots control valve devices, so that when the levers I42 thereof are in the positions indicated by lines 386, the full pressure of fluid in pipe 65 becomes efiective in chambers II2 on the diaphragms of the regulating valve devices. This pressure is however limited by the pressure regulating valve device 224 to a degree such as pounds in contrast to the relatively higher pressure such as 400 pounds in the supply reservoir 39 and 49, and the purpose of this is to avoid rupturing the diaphragm III in said regulating devices, as might occur if subjected to the higher pressure.

The spring chambers H3 in the blower regulating devices 8 are open to the sump reservoir 32 so that the pressure in said chambers will vary with that in said reservoirs. This, however, will have no effect upon the operation of these regulating devices since the pressure of fluid supplied to chamber II2 therein will always exceed the sump reservoir pressure and insure intended operation of the devices.

The pressure regulating device 224 associated with the engineers control devices I! to I4 and hereinbefore described is provided for limiting the diiferential of pressures on the diaphragms II! in the blower regulating devices 8 as just described, and on diaphragms 243 in the several control transfer valve devices 24! in the engineers control valve devices I I to I4 and serves no other purpose. In this connection it may be pointed out that the diaphragms in the engineers speed regulating valve devices 242 and in the mixture and heat regulating valve devices It to 23 do not require this protection since these diaphragms are never subject to fluid at the pressure in the supply reservoirs and may never be subjected to a differential in pressures exceeding a degree such as 150 pounds as limited by the control springs.

Description-Figure 12 In the control apparatus above described the ring seals 85, 98 and I I3 are required in the speed regulating devices 5, and in the mixture, heat and blower regulating devices 6, I, and 8 respectively, to prevent leakage of fluid under pressure to the atmosphere from the chambers therein which are open to the sump reservoir 32, and it is necessary that these chambers be connected to the sump reservoir in order that the effect of variations in pressure in the sump reservoir on the control diaphragms in the pilots control valve device I9 and in the different engineers control valve devices I to I4 and I3 to 23 be offset, and thus have no influence upon the adjustment of said regulating devices in response to operation of said control valve devices.

The ring seals 85, 98 and H6 in the regulating valve devices 5 to 8 and the pipes connecting said devices with the sump reservoir 32 in the apparatus above described, may be eliminated by use of a structure such as shown in Figs. 12 to 14 wherein sump reservoir pressure acting in the pilots and engineers control valve devices has no effect upon the pressure of fluid supplied by said control valve devices for controlling said regulating devices.

In Fig. 12 are shown only the speed, mixture, heat, and blower regulating devices for one engine, and the engineers control valve devices, 

